import java.util.Scanner;

public class Solution1 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        //1. 读入数据
        int n = in.nextInt();
        int q = in.nextInt();
        int[] arr = new int[n + 1];
        for(int i = 1; i <= n; i++) {
            arr[i] = in.nextInt();
        }
        //2. 预处理一个前缀和数组
        long[] dp = new long[n + 1]; //防止溢出
        dp[0] = 0;
        for(int i = 1; i <= n; i++) {
            dp[i] = dp[i - 1] + arr[i];
        }

        //3. 使用前缀和数组
        while(q > 0) {
            int l = in.nextInt();
            int r = in.nextInt();
            System.out.println(dp[r] - dp[l - 1]);
            q--;
        }
    }
}